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Results for “immunology”

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bioRxiv2021

Systemic delivery of a CXCR4-CXCL12 signaling inhibitor encapsulated in synthetic protein nanoparticles for glioma immunotherapy

Glioblastoma multiforme (GBM) is an aggressive primary brain tumor, with poor prognosis. Major obstacles hampering effective therapeutic response in GBM are tumor heterogeneity, high infiltration of immunosuppressive myeloid cells, and the presence of the blood-brain barrier. The C-X-C Motif Chemokine Ligand 12/ C-X-C Motif Chemokine Receptor 4 (CXCL12/ CXCR4) signaling pathway is implicated in GBM invasion and cell cycle progression. While the CXCR4 antagonists (AMD3100) has a potential anti-GBM effects, its poor pharmacokinetic and systemic toxicity had precluded its clinical application. Moreover, the role of CXCL12/ CXCR4 signaling pathway in anti-GBM immunity, particularly in GBM-mediated immunosuppression has not been elucidated. Here, we developed a synthetic protein nanoparticle (SPNPs) coated with the cell-penetrating peptide iRGD (AMD3100 SPNPs) to target the CXCR4/CXCL12 signaling axis in GBM. We showed that AMD3100 SPNPs effectively blocked CXCR4 signaling in mouse and human GBM cells in vitro as well as in GBM model in vivo. This results in inhibition of GBM proliferation and induction of immunogenic tumor cell death (ICD) leading to inhibition of GBM progression. Our data also demonstrate that blocking CXCR4 sensitizes GBM cells to radiation, eliciting enhanced release of ICD ligands. Combining AMD3100 SPNPs with radiotherapy inhibited GBM progression and led to long-term survival; with 60% of mice remaining tumor-free. This was accompanied by an anti-GBM immune response and sustained immunological memory that prevented tumor recurrence without further treatment. Finally, we showed that systemic delivery of AMD3100 SPNPs decreased the infiltration of CXCR4+ monocytic myeloid-derived suppressor cells to the tumor microenvironment. With the potent ICD induction and reprogrammed immune microenvironment, this strategy has significant potential for future clinical translation. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=141 SRC="FIGDIR/small/457953v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@17c9377org.highwire.dtl.DTLVardef@1b5a4dcorg.highwire.dtl.DTLVardef@5aa4eaorg.highwire.dtl.DTLVardef@1011a86_HPS_FORMAT_FIGEXP M_FIG Immunological mechanism targeting Glioblastoma (GBM) upon blocking CXCR4 signaling pathway with AMD3100-conjugated nanoparticles (SPNPs). (1) Radiotherapy induces glioma cell death, followed by Damage-associated molecular patterns (DAMPs) release. Dendritic cells (DC) are activated by DAMPs and migrate to the regional lymph node where they prime cytotoxic T lymphocyte immune response. Tumor-specific cytotoxic T cells infiltrate the tumor and attack glioma cells. (2) Glioma cells express CXCR4, as well its ligand CXCL12. CXCL12 induces glioma cell proliferation and, (3) as well as mobilization in the bone marrow of CXCR4 expressing myeloid MDSC, which will infiltrate the tumor, and inhibit tumor-specific cytotoxic T cells activity. GEMM of glioma when treated systemically with SPNPs AMD3100 SPNPs plus radiation, nanoparticles block the interaction between CXCR4 and CXCL12, thus (4) inhibiting glioma cell proliferation and (5) reducing mobilization in the bone marrow of CXCR4 expressing myeloid MDSC, (6) generating a reduced MDSC tumor infiltration, as well as releasing MDSC inhibition over tumor specific cytotoxic T cell response. C_FIG

cell biology↗

bioRxiv2021

Immunity vs Sociality: Adaptive evolution tests suggest social lifestyle exerts greater selection pressures than host-pathogen coevolution in the bees

Hosts and their parasites and pathogens are locked in antagonistic co-evolution. The genetic consequence of this can be seen in the rates of adaptive evolution in immunologically important loci in many taxa. As the risk of disease transmission increases we might also expect to see greater rates of adaptive evolution on genes of immune function. The evolution of sociality and its elaborations in insects represent enormous shift in disease transmission risk. Here, we examine whether sociality in the bees corresponds to changes in the rate of adaptive evolution in both classical canonical immune genes, and genes with putative immune functions identified from meta-analyses of honey-bee transcriptomic responses to infection. We find that measures of gene-wide adaptive evolution do not differ among canonical immune, non-canonical candidate immune, and background gene sets, but that branch-site adaptive evolution does increase with sociality regardless of gene category. Solitary species have greater rates of adaptive evolution in canonical immune genes than background genes, supporting the suggestion that social immune mechanisms may instead be the site of host-pathogen co-evolution in social species. We identify three genes with putative roles in immunity that warrant further attention (Vitel-logenin Vg, disks large 1 tumour suppressor, and the uncharacterised protein LOC100577972). There are more gene family changes after the origin of sociality across all gene classes, with contractions occur-ring after the elaboration of sociality to complex eusociality. There are few genes or functions under adaptive selection that appear to be shared outside of specific lineages, suggesting that evolution of the immune system may be specific to individual species and their pathogen interactions. SignificanceInfectious disease drives rapid evolution of immune genes, but infection risk should be much higher in social species. To examine whether greater sociality drives faster immune system evolution we compared the rate of immune gene evolution in solitary, social, and highly eusocial bees. To account for possible novel immune genes in bees, we analysed classical immune genes alongside candidate immune genes inferred from other studies. Surprisingly, we find that solitary bees have the highest rate of immune gene evolution relative to background genes but that sociality is associated with rapid evolution across the whole genome. These findings suggest that 1) accelerated immune gene evolution is not universal, 2) immune gene evolution is moderated by sociality in that solitary species invest more into immune gene change, and 3) that social genomes are highly dynamic, which may obscure evolution at immunological loci. The types of immune genes and functions appear mostly lineage-specific, regardless of sociality, suggesting individual evolutionary his-tories exert more selection pressure than general patterns of greater pathogen exposure introduced by social living.

evolutionary biology↗

bioRxiv2021

Tumor cell intrinsic and extrinsic features predicts prognosis in estrogen receptor positive breast cancer

Although estrogen-receptor-positive (ER+) breast cancer is generally associated with favorable prognosis, clinical outcome varies substantially among patients. Genomic assays have been developed and applied to predict patient prognosis for personalized treatment. We hypothesize that the recurrence risk of ER+ breast cancer patients is determined by both genomic mutations intrinsic to tumor cells and extrinsic immunological features in the tumor microenvironment. Based on the Cancer Genome Atlas (TCGA) breast cancer data, we identified the 72 most common genomic aberrations (including gene mutations and indels) in ER+ breast cancer and defined sample-specific scores that systematically characterized the deregulated pathways intrinsic to tumor cells. To further consider tumor cell extrinsic features, we calculated immune infiltration scores for six major immune cell types. Many individual intrinsic features are predictive of patient prognosis in ER+ breast cancer, and some of them achieved comparable accuracy with the Oncotype DX assay. In addition, statistical learning models that integrated these features predicts the recurrence risk of patients with significantly better performance than the Oncotype DX assay. As a proof-of-concept, our study indicates the great potential of genomic and immunological features in prognostic prediction for improving breast cancer precision medicine. The framework introduced in this work can be readily applied to other cancers. Author SummaryMany genomic biomarker tests such as Oncotype DX have been developed for breast cancer and have helped guide clinical decisions. We have developed gene signatures to integrate cancer genomic and transcriptomic data to characterize the downstream effect of driver genomic events. These signatures recapitulate the de-regulated pathways underlying the corresponding driver genomic events and are more correlated with clinical phenotypes such as recurrence free survival than mutation status alone. We apply this framework to ER+ breast cancer and define gene signatures for a total of 72 most commonly observed genomic events including gene mutations, amplifications and deletions. We find that many of these gene signatures are predictive of patient prognosis in ER+ breast cancer, and some of them achieved comparable accuracy with the Oncotype DX assay. We combine these tumor-intrinsic signatures with infiltration signatures for major immune cell types (tumor-extrinsic features) to construct integrative models for prognosis prediction. The models predicts the recurrence risk of patients with significantly better performance than the Oncotype DX assay.

genomics↗

bioRxiv2021

The SKBR3 Cell-Membrane Proteome: Role in Aberrant Cancer Cell Proliferation and Resource for Precision Medicine Applications

The plasma membrane proteome resides at the interface between the extra- and intra-cellular environment and through its various roles in signal transduction, immune recognition, nutrient transport, and cell-cell and cell-matrix interactions plays an absolutely critical role in determining the fate of a cell. Our work was aimed at exploring the landscape of the cancer cell-membrane proteome responsible for sustaining uncontrolled cell proliferation, and its intrinsic resources for enabling detection and therapeutic interventions. SKBR3/HER2+ breast cancer cells were used as a model system and mass spectrometry for characterizing the proteome. The number of identified cell-membrane proteins exceeded 2,000, with ~1,300 being matched by two or more unique peptides. Classification in four major categories, i.e., proteins with receptor or enzymatic activity, CD antigens, transporters, and cell adhesion proteins, uncovered overlapping roles in biological processes that drive cell growth, apoptosis, differentiation, immune response, adhesion and migration, as well as capabilities for signaling crosstalk and alternate pathways for proliferation. The large number of tumor markers (>50) and putative drug targets (>100) exposed a vast potential for yet unexplored detection and targeting opportunities, whereas the presence of 15 antigen immunological markers enabled an assessment of epithelial, mesenchymal or stemness characteristics. Serum-starved cells displayed altered processes related to mitochondrial OXPHOS/ATP synthesis, protein folding and localization, while serum-treated cells exhibited attributes that support tissue invasion and metastasis. Altogether, our findings advance the understanding of the biological triggers that sustain aberrant cancer cell proliferation, survival and development of resistance to therapeutic drugs, and reveal the vast innate opportunities for guiding immunological profiling and precision medicine applications aimed at target selection or drug discovery.

cancer biology↗

bioRxiv2021

Microglia do not restrict SARS-CoV-2 replication following infection of the central nervous system of K18-hACE2 transgenic mice

Unlike SARS-CoV-1 and MERS-CoV, infection with SARS-CoV-2, the viral pathogen responsible for COVID-19, is often associated with neurologic symptoms that range from mild to severe, yet increasing evidence argues the virus does not exhibit extensive neuroinvasive properties. We demonstrate SARS-CoV-2 can infect and replicate in human iPSC-derived neurons and that infection shows limited anti-viral and inflammatory responses but increased activation of EIF2 signaling following infection as determined by RNA sequencing. Intranasal infection of K18 human ACE2 transgenic mice (K18-hACE2) with SARS-CoV-2 resulted in lung pathology associated with viral replication and immune cell infiltration. In addition, [~]50% of infected mice exhibited CNS infection characterized by wide-spread viral replication in neurons accompanied by increased expression of chemokine (Cxcl9, Cxcl10, Ccl2, Ccl5 and Ccl19) and cytokine (Ifn-{lambda} and Tnf-) transcripts associated with microgliosis and a neuroinflammatory response consisting primarily of monocytes/macrophages. Microglia depletion via administration of colony-stimulating factor 1 receptor inhibitor, PLX5622, in SARS-CoV-2 infected mice did not affect survival or viral replication but did result in dampened expression of proinflammatory cytokine/chemokine transcripts and a reduction in monocyte/macrophage infiltration. These results argue that microglia are dispensable in terms of controlling SARS-CoV-2 replication in in the K18-hACE2 model but do contribute to an inflammatory response through expression of pro-inflammatory genes. Collectively, these findings contribute to previous work demonstrating the ability of SARS-CoV-2 to infect neurons as well as emphasizing the potential use of the K18-hACE2 model to study immunological and neuropathological aspects related to SARS-CoV-2-induced neurologic disease. ImportanceUnderstanding the immunological mechanisms contributing to both host defense and disease following viral infection of the CNS is of critical importance given the increasing number of viruses that are capable of infecting and replicating within the nervous system. With this in mind, the present study was undertaken to evaluate the role of microglia in aiding in host defense following experimental infection of the central nervous system (CNS) of K18-hACE2 with SARS-CoV-2, the causative agent of COVID-19. Neurologic symptoms that range in severity are common in COVID-19 patients and understanding immune responses that contribute to restricting neurologic disease can provide important insight into better understanding consequences associated with SARS-CoV-2 infection of the CNS.

microbiology↗

bioRxiv2021

The impact of Piscirickettsia Salmonis infection on genome-wide DNA methylation profile in Atlantic Salmon

Salmon rickettsial septicaemia (SRS), caused by the intracellular bacteria Piscirickettsia Salmonis, generates significant mortalities to farmed Atlantic salmon, particularly in Chile. Due to its economic importance, a wealth of research has focussed on the biological mechanisms underlying pathogenicity of P. salmonis, the host response, and genetic variation in host resistance. DNA methylation is a fundamental epigenetic mechanism that influences almost every biological process via the regulation of gene expression and plays a key role in the response of an organism to stimuli. In the current study, the role of head kidney and liver DNA methylation in the response to P. salmonis infection was investigated in a commercial Atlantic salmon population. A total of 66 salmon were profiled using reduced representation bisulphite sequencing (RRBS), with head kidney and liver methylomes compared between infected animals (3 and 9 days post infection) and uninfected controls. These included groups of salmon with divergent (high or low) breeding values for resistance to P. salmonis infection, to examine the influence of genetic resistance. Head kidney and liver showed organ-specific global methylation patterns, but with similar distribution of methylation across gene features. Integration of methylation with RNA-Seq data revealed that methylation levels predominantly showed a negative correlation with gene expression, although positive correlations were also observed. Methylation within the first exon showed the strongest negative correlation with gene expression. A total of 911 and 813 differentially methylated CpG sites were identified between infected and control samples in the head kidney at 3 and 9 days respectively, whereas only 30 and 44 sites were differentially methylated in the liver. Differential methylation in the head kidney was associated with immunological processes such as actin cytoskeleton regulation, phagocytosis, endocytosis and pathogen associated pattern receptor signaling. We also identified 113 and 48 differentially methylated sites between resistant and susceptible fish in the head kidney and liver respectively. Our results contribute to the growing understanding of the role of methylation in regulation of gene expression and response to infectious diseases, and in particular reveal key immunological functions regulated by methylation in Atlantic salmon in response to P. salmonis.

genomics↗

bioRxiv2021

Transcriptomic Profiling Reveals Cancer-Associated Fibroblasts as Potential Targets for the Prognosis and Treatment of Cervical Squamous Cell Carcinoma

Effective treatment of advanced invasive cervical cancer remains challenging nowadays. Herein, single-nucleus RNA sequencing (snRNA-seq) and SpaTial Enhanced REsolution Omics-sequencing (Stereo-seq) technology are used to investigate the immunological microenvironment of cervical squamous cell carcinoma (CSCC), a major type of cervical cancers. The expression levels of most immune checkpoint genes in tumor and inflammation areas of CSCC were not significantly higher than those in the non-cancer samples except for LGALS9 and IDO1. Stronger signals of CD56+ NK cells and immature dendritic cells are found in the hypermetabolic tumor areas, while more eosinophils, immature B cells, and Treg cells are found in the hypometabolic tumor areas. Moreover, a cluster of cancer-associated fibroblasts (CAFs) are identified around some tumors, which highly expressed ACTA2, POSTN, ITGB4, and FAP. The CAFs might support the growth and metastasis of tumors by inhibiting lymphocyte infiltration and remodeling the tumor extracellular matrix. Furthermore, CAFs are associated with poorer survival probability in CSCC patients and might be present in a small fraction ([~]20%) of advanced cancer patients. Collectively, these findings might enhance understanding of the CSCC immunological microenvironment and shed some light on the treatment of advanced CSCC.

cancer biology↗

bioRxiv2022

AI-assisted Discovery of an Ethnicity-influenced Driver of Cell Transformation in Esophageal and Gastroesophageal Junction Adenocarcinomas

Although Barretts metaplasia of the esophagus (BE) is the only known precursor lesion to esophageal adenocarcinomas (EACs), drivers of the metaplasia[->]dysplasia[->]neoplasia cascade in the esophagus remains incompletely understood. Using an AI-guided network transcriptomics approach, in which EAC initiation and progression is modeled as networks to simplify complex multi-cellular processes, we first predict cellular continuum states and disease driving processes with an unprecedented degree of precision. Key AI-guided predictions are subsequently validated in a human organoid model and patient-derived biopsies of BE, a case-control study of genomics of BE progression, and in a cross-sectional study of 113 patients with BE and EACs. We find that all EACs must originate from BE, pinpoint a CXCL8/IL8{leftrightarrow}neutrophil immune microenvironment as a driver of cellular transformation in both EACs and gastroesophageal junction-ACs. This driver is prominent in Caucasians (Cau), but notably absent in African Americans (AAs). Network-derived gene signatures, independent signatures of neutrophil processes, CXCL8/IL8, and an absolute neutrophil count (ANC) are associated with risk of progression. SNPs associated with ethnic changes in ANC modify that risk. Thus, findings define a racially influenced immunological basis for cell transformation and suggest that benign ethnic neutropenia in AAs may serve as a deterrent to BE[->]EAC progression. BRIEF SUMMARYEsophageal adenocarcinoma (EAC) is a highly lethal cancer among Caucasians, while African Americans are somewhat protected; what factors drive transformation with racial disparity remain unknown. AI-enabled creation of the first computational map of neoplastic progression in the esophagus built and validated using transcriptomic datasets from diverse cohorts of human samples pinpointed CXCL8{leftrightarrow}neutrophil tumor immune-microenvironment as a racially influenced driver of EACs and GEJ-ACs. Computational tools pinpoint a racially influenced driver of cell transformation during BE[->]EAC progression; in doing so, it reveals new novel biology, informs disease modeling, therapeutic strategies, and biomarkers. LAY SUMMARYBy modeling diseases as networks, this work unravels a fundamental race-influenced immunologic driver of cell transformation in adenocarcinomas of the esophagus and the gastroesophageal junction.

cancer biology↗

bioRxiv2022

Distinct Core Glycan and O-Glycoform Utilization of SARS-CoV-2 Omicron Variant Spike Protein RBD Revealed by Top-Down Mass Spectrometry

The SARS-CoV-2 Omicron (B.1.1.529) variant possesses numerous spike (S) mutations particularly in the S receptor-binding domain (S-RBD) that significantly improve transmissibility and evasion of neutralizing antibodies. But exactly how the mutations in the Omicron variant enhance viral escape from immunological protection remains to be understood. The S-RBD remains the principal target for neutralizing antibodies and therapeutics, thus new structural insights into the Omicron S-RBD and characterization of the post-translational glycosylation changes can inform rational design of vaccines and therapeutics. Here we report the molecular variations and O-glycoform changes of the Omicron S-RBD variant as compared to wild-type (WA1/2020) and Delta (B.1.617.2) variants using high-resolution top-down mass spectrometry (MS). A novel O-glycosite (Thr376) unique to the Omicron variant is identified. Moreover, we have directly quantified the Core 1 and Core 2 O-glycan structures and characterized the O-glycoform structural heterogeneity of the three variants. Our findings reveal high resolution detail of Omicron O-glycoforms and their utilization to provide direct molecular evidence of proteoform alterations in the Omicron variant which could shed light on how this variant escapes immunological protection.

biochemistry↗

bioRxiv2022

Lyophilization induces alterations in cryptococcal exopolysaccharide resulting in reduced antibody binding

The structural, antigenic, and immunological characterization of microbial polysaccharides requires purification that often involves detergent precipitation and lyophilization. Here we examine physicochemical changes induced by lyophilization on exopolysaccharide (EPS) of the pathogenic fungus Cryptococcus neoformans. Solution 1H NMR reveals significant anomeric signal attenuation following lyophilization of native EPS while 1H ssNMR shows few changes, suggesting diminished molecular motion and consequent broadening of 1H NMR polysaccharide resonances. 13C ssNMR, dynamic light scattering, and transmission electron microscopy show that, while native EPS has rigid molecular characteristics and contains small, loosely packed polysaccharide assemblies, lyophilized and resuspended EPS is disordered and contains larger dense rosette-like aggregates, suggesting that structural water molecules in the interior of the polysaccharide assemblies are removed during extensive lyophilization. Importantly, mAbs to C. neoformans polysaccharide binds the native EPS more strongly than lyophilized EPS. Together, these observations argue for caution when interpreting the biological and immunological attributes of polysaccharides that have been lyophilized to dryness.

microbiology↗

bioRxiv2022

Splenic clearance of rigid erythrocytes as an inherited mechanism for splenomegaly and natural resistance to malaria

In malaria-endemic areas, subjects from specific groups like Fulani have a peculiar protection against malaria, with high levels of IgM but also frequent anemia and splenomegaly. The mechanisms underlying this phenotype remain elusive. In Benin, West Africa, we measured the deformability of circulating erythrocytes in genetically distinct groups (including Fulani) living in sympatry, using ektacytometry and microsphiltration, a mimic of how the spleen clears rigid erythrocytes. Compared to non-Fulani, Fulani displayed a higher deformability of circulating erythrocytes, pointing to an enhanced clearance of rigid erythrocytes by the spleen. This phenotype was observed in individuals displaying markers of Plasmodium falciparum infection. The heritability of this new trait was high, with a strong multigenic component. Five of the top 10 genes selected by a population structure-adjusted GWAS, expressed in the spleen, are potentially involved in splenic clearance of erythrocytes (CHERP, MB, PALLD, SPARC, PDE10A), through control of vascular tone, collagen synthesis and macrophage activity. In specific ethnic groups, genetically-controlled processes likely enhance the innate retention of infected and uninfected erythrocytes in the spleen, explaining splenomegaly, anemia, cryptic intrasplenic parasite loads, hyper-IgM, and partial protection against malaria. Beyond malaria-related phenotypes, inherited splenic hyper-filtration of erythrocytes may impact the pathogenesis of other hematologic diseases. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSThe genetic background of individuals influences their susceptibility to infectious diseases. Specific human groups, like the Fulani in Africa, react to malaria parasites (named Plasmodium) in a specific way. Upon infection, Fulani develop a grossly enlarged spleen, and high levels of anti-Plasmodium antibodies in their blood. They also carry smaller numbers of parasites in their blood, and thus are considered partially protected against malaria. The mechanisms underlying this natural protection, different from other natural protective mechanisms such as the sickle cell trait, are not well understood. Malaria impairs the deformability of red blood cells and the spleen is a key organ to controlling red blood cell quality. We have recently demonstrated that red blood cells containing live malaria parasites accumulate intensely in the spleen of subjects with long term exposure to these parasites. Enhanced retention of infected and uninfected red blood cells in the spleen would explain why the spleen is larger and why lower numbers of parasites are left in circulation. We thus explored whether the retention of infected and uninfected red blood cells could explain why Fulani are partially protected against malaria. Because it is unethical to perform spleen puncture or biopsies for research purposes, our explorations were indirect by carefully analyzing the properties of circulating red blood cells in a large number of subjects and by assessing whether observations could be explained by their genetic make-up. Added value of this studyIn more than 500 subjects, we confirmed the high frequency of large spleens in Fulani and, through 2 different methods, we demonstrated an enhanced deformability of their circulating red blood cells, that likely stems from the more efficient removal of the less deformable ones. This enhanced deformability was found to be inheritable based on carefully collected family links and refined analysis of genetic markers. Implications of all the available evidenceOur findings indicate that genes potentially driving the filtration of red blood cells by the spleen likely influence how subjects in specific groups in Africa and elsewhere react to malaria. While most previous hypotheses pointed to conventional immunological mechanisms as the trigger, we propose that a simple physiological mechanism that controls the quality of red blood cells may drive natural protection from malaria even before the intervention of immunological cells. A better understanding of these processes is of great importance in the context of malaria elimination efforts. These findings may also have an impact on the understanding of other red blood cell-related disorders, such as inherited red cell diseases, in which splenic filtration of abnormal red blood cells may precipitate splenic complications.

physiology↗

bioRxiv2022

Epitope-Evaluator: an interactive web application to study predicted T-cell epitopes

Multiple immunoinformatic tools have been developed to predict T-cell epitopes from protein amino acid sequences for different major histocompatibility complex (MHC) alleles. These prediction tools output hundreds of potential peptide candidates which require further processing; however, these tools are either not graphical or not friendly for non-programming users. We present Epitope-Evaluator, a web tool developed in the Shiny/R framework to interactively analyze predicted T-cell epitopes. This includes providing the distribution of epitopes across a selected set of MHC alleles, the promiscuity and conservation of epitopes, and their density and location within antigens. Epitope-Evaluator requires as input the fasta file of protein sequences and the output prediction file coming out from any predictor. By choosing different cutoffs and parameters, users can produce several interactive plots and tables that can be downloaded as JPG and text files, respectively. Epitope-Evaluator removes the programming barrier and provides intuitive tools, allowing a straightforward interpretation and graphical representations that facilitate the selection of candidate epitopes for experimental evaluation. Author SummaryWith the advent of the COVID-19 pandemic as well as past pandemics and epidemics, scientists have focused on immunological studies to develop better vaccines as well as understand immune responses. Many of the questions are centered on studying T-cell epitopes, and peptide sequences that can be presented to immune cells to elicit responses against pathogens. Although current software can produce hundreds of predictions, they are generally not user-friendly nor graphical. In order to remove the existing programming barrier, we developed a Web tool to allow scientists to analyze and filter T-cell epitopes in an easy, intuitive, interactive, and versatile way. We have included two biological cases identifying new biological insights and showing the importance of having this type of toolset, especially for nonprogrammer researchers in the immunology field.

bioinformatics↗

bioRxiv2022

Phylogenomic diversity elucidates mechanistic insights into Lyme borreliae host association

Host association- the selective adaptation of pathogens to specific host species - evolves through constant interactions between host and pathogens, leaving a lot yet to be discovered on immunological mechanisms and genomic determinants. The causative agents of Lyme disease (LD) are spirochete bacteria composed of multiple species of the Borrelia burgdorferi sensu lato complex, including B. burgdorferi (Bb), the main LD pathogen in North America - a useful model for the study of mechanisms underlying host-pathogen association. Host adaptation requires pathogens ability to evade host immune responses, such as complement, the first-line innate immune defense mechanism. We tested the hypothesis that different host adapted phenotypes among Bb strains are linked to polymorphic loci that confer complement evasion traits in a host-specific manner. We first examined the survivability of 20 Bb strains in sera in vitro and/or bloodstream and tissues in vivo from rodent and avian LD models. Three groups of complement-dependent host association phenotypes emerged. We analyzed complement-evasion genes, identified a priori among all strains and sequenced and compared genomes for individual strains representing each phenotype. The evolutionary history of ospC loci is correlated with host-specific complement-evasion phenotypes, while comparative genomics suggests several gene families and loci are potentially involved in host association. This multidisciplinary work provides novel insights into the functional evolution of host adapted phenotypes, building a foundation for further investigation of the immunological and genomic determinants of host association. IMPORTANCEHost association is the phenotype that is commonly found in many pathogens that preferential survive in particular hosts. The Lyme disease (LD) causing agent, B. burgdorferi (Bb), is an ideal model to study host association, as Bb is mainly maintained in nature through rodent and avian hosts. A widespread yet untested concept posits that host association in Bb strains is linked to Bb functional genetic variation conferring evasion to complement, an innate defense mechanism in vertebrate sera. Here, we tested this concept by grouping 20 Bb strains into three complement-dependent host association phenotypes based on their survivability in sera and/or bloodstream and distal tissues in rodent and avian LD models. Phylogenomic analysis of these strains further correlated several gene families and loci, including ospC, with host-specific complement-evasion phenotypes. Such multifaceted studies thus pave the road to further identify the determinants of host association, providing mechanistic insights into host-pathogen interaction.

microbiology↗

bioRxiv2022

Identification of genomic regions implicated in susceptibility to Schistosoma mansoni infection in a murine genetic model (backcross)

High levels of infection and severe liver fibrosis in schistosomiasis appear only in a few cases of infected people with high susceptibility. Tissue damage is caused by the inflammatory response to eggs trapped in the liver. The genetic background influences susceptibility to schistosome infection. To assess the genetic basis of susceptibility to schistosomiasis and identify the chromosomic regions involved, we used a backcross strategy to generate a mouse cohort with high variation in schistosomiasis susceptibility. Thus, we crossed the resistant C57BL/6 mouse strain with the susceptible CBA one; and later; the F1 females (C57 x CBA) were backcrossed with CBA males generating the F1BX cohort. The spectrum of phenotypes in the F1BX mice showed gradation from mild to severe disease, lacking a fully resistant group. We differentiated four levels of infection intensity using cluster and principal component analyses and K-means based on parasitological, pathological and immunological trait measurements. Mice were massively genotyped with 961 informative SNPs. We identify 19 new quantitative trait loci (QTL) associated with phenotype indicators of parasite burden, liver lesion, white blood cell populations, and antibody responses evaluated in the backcross cohort. Two QTLs on chromosomes 15 and 18 were simultaneously linked to the number of granulomas, grade of liver lesion and IgM levels. The human syntenic regions are located in chromosomes 8 and 18. None of the significant QTL identified coincided with previously reported mice association or were syntenic with human chromosomes. Author summaryHigh number of cases of infection and high levels of infection and liver fibrosis in schistosomiasis appear only in a few cases of people with high susceptibility, because the genetic background influences this susceptibility. To assess this, we used a backcross strategy crossing a resistant strain of mouse C57BL/6 with another susceptible CBA, and later F1 females were backcrossed with males susceptible, generating the F1BX cohort, which showed gradation from mild to severe disease. We differentiated four levels of infection according to cluster, principal component analysis and K-means, and based on parasitological, pathological and immunological measurements. Mice were massively genotyped and 19 quantitative trait loci (QTL) were identified, associated with phenotype indicators evaluated in backcross cohort. Two QTLs on chromosomes 15 and 18 were simultaneously linked to the number of granulomas, grade of liver lesion and IgM levels. None of the significant QTL identified coincided with previously reported mice association or were syntenic with human chromosomes.

pathology↗

bioRxiv2022

Reprogramming brain immunosurveillance with engineered cytokines

Immune surveillance of the brain is regulated by resident non-neuronal cells and the blood-brain barrier.1 Dys-regulation of immunosurveillance is a hallmark feature of several diseases2-5 including brain tumors6 that interact with and rely heavily on immune cells,7 suggesting that disrupting the neuroimmunology of tumors could slow their progression. Yet few tools are available to control brain immunology in vivo with local precision, and fewer yet are used for therapeutic intervention. 2 Here, we propose engineered cytokines as a neuroimmune-modulation platform. We demonstrate that the residence time of cytokines in the brain can be tuned by binding them to the extracellular matrix or synthetic scaffolds. We then show that the aluminum hydroxide adjuvant (alum) is retained in the brain >2 weeks. Tethering of inflammatory cytokines such as interleukins (IL) 2 and 12 to alum yields extended neuroinflammation and brain immunosurveillance after intracranial administration, while avoiding systemic toxicity. In mouse models of both immunologically hot and cold brain tumors, the intracranial deposition of alum-tethered cytokines causes significant delay in tumor progression. RNA profiling reveals that engineered cytokines engage both innate and adaptive immunity in the brain. These findings suggest that engineered cytokines can reprogram brain immunosurveillance, informing the development of future therapies for neuroimmune diseases.

bioengineering↗

bioRxiv2022

Differential migration mechanics and immune responses of glioblastoma subtypes

Glioblastoma remains a deadly cancer driven in part by invasion of tumor cells into the brain. Transcriptomic analyses have identified distinct molecular subtypes, but mechanistic differences that account for clinical differences are not clear. Here, we show that, as predicted by the motor-clutch model of cell migration, mesenchymal glioma cells are more spread, generate larger traction forces, and migrate faster in brain tissue compared to proneural cells. Despite their rapid migration and comparable proliferation rates in vitro, mice with mesenchymal tumors survive longer than those with proneural tumors. This improved survival correlated with an immune response in the mesenchymal tumors, including T cell-mediated. Consistently, inducing mesenchymal tumors in immunodeficient mice resulted in shorter survival supporting a protective immune role in mesenchymal tumors. Thus, mesenchymal tumors have aggressive migration, but are immunologically hot which suppresses net proliferation. These two features counteract each other and may explain the lack of a strong survival difference between subtypes clinically, while also opening up new opportunities for subtype-specific therapies. Significant StatementThis study highlights new mechanical and immunological insights into glioblastoma molecular subtypes using an integrated modeling-genome engineering strategy, which can potentially facilitate glioblastoma subtype-specific therapeutic strategies.

cancer biology↗

bioRxiv2022

Inactivated SARS-CoV-2 Reprograms the Tumor Immune Microenvironment and Improves Murine Cancer Outcomes

Following the breakthrough of immune check point inhibitors (ICIs), a new era of immuno-oncology agents has emerged and established immunotherapy as a part of cancer treatment. Despite the improving outcomes of ICIs, many patients with initial response are known to develop acquired resistance later. There is increasing interest in utilizing other stimulatory means, such as anti-pathogen immune responses to induce anti-tumor immune responses. The immunostimulatory effects of anti-pathogen-treated tumors in combinations with ICI are known to potentially amplify anti-tumor immunity resulting in increased tumor responses and improved outcomes. Anti-pathogen-treated tumors can become immune-infiltrated "hot" tumors and demonstrate higher treatment response rates and improved survival. Our research group has previously demonstrated that tumors can be converted from "cold" to "hot" by intratumoral injection of a commercially available seasonal influenza vaccine. In continuation with our work, in deciphering the role of anti-viral immunity in the context of tumor immunology, we studied the role of inactivated SARS-CoV-2 virus as anti-tumor agent. Here we report that intratumoral injections of inactivated SARS-CoV-2 convert the immunologically cold tumors to hot by generating anti-tumor-mediated CD8+ T cells. Our findings suggest that inactivated SARS-CoV-2 can be used as an immune modulator in immunotherapy for melanoma and triple-negative breast cancer.

cancer biology↗

bioRxiv2022

Artificial immune cell, AI-cell, a new tool to predict interferon production by peripheral blood monocytes in response to nucleic acid nanoparticles

Nucleic acid nanoparticles, or NANPs, are rationally designed to communicate with the human immune system and can offer innovative therapeutic strategies to overcome the limitations of traditional nucleic acid therapies. Each set of NANPs is unique in their architectural parameters and physicochemical properties, which together with the type of delivery vehicles determine the kind and the magnitude of their immune response. Currently, there are no predictive tools that would reliably guide NANPs design to the desired immunological outcome, a step crucial for the success of personalized therapies. Through a systematic approach investigating physicochemical and immunological profiles of a comprehensive panel of various NANPs, our research team has developed a computational model based on the transformer architecture able to predict the immune activities of NANPs via construction of so-called artificial immune cell, or AI-cell. The AI-cell will aid addressing in timely manner the current critical public health challenges related to overdose and safety criteria of nucleic acid therapies and promote the development of novel biomedical tools.

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